GASTEROPODA. 115 



The figure is lengthened, almost subulate, the convexity of the volutions being but 

 slight ; their transverse diameter exceeds their length by about one third. Longitudinal 

 dimensions 5 lines, transverse diameter 2 lines. 



Locality. Near Scarborough. 



Cerithium gemmatum. Plate XV, fig. 6. 



C. Testa parvd, turritd ; anfractibus convexiusculis, nodulis cinyillatisque 5 ; nodulis 

 ovatis subdistantibus, circa 24 in ambitu. 



Shell small, turreted ; volutions rather convex, encircled with five rows of nodules ; 

 nodules ovate, about 24 in a volution ; the rows of nodules are slightly curved, and the 

 last volution has from 7 to 9 rows. 



The little nodules are regular, oval, their longer diameter being in the axis of the shell, 

 and they are distant from each other about their own diameter ; the number of volutions 

 are but few, apparently not more than 7. Length 7 lines, transverse diameter 2 lines. 



Locality. Great Oolite near Scarborough. 



Chemnitzia ? Scarburgensis. Plate XV, fig. 8. 



C. Testa magna, pyramidato-turritd, lavi ; anfractibus subplanis ad suturas subplicatis, 

 aut vittd latiusculd transversa, plus minusve convexd notatis ; aperturd ovatd, superne 

 strictissimd ; columella maryinatd, supra subcallosd. ? 



Shell large, pyramidal, turreted, smooth ; whorls nearly flat, but with one fold near to 

 their sutures, or with a broad transverse band more or less convex ; aperture ovate, very 

 narrow above ; columella marginated, thickened above. 



The upper border of the whorls is slightly turned, their junctions are strongly defined. 

 The longitudinal diameter of the penultimate whorl is 7 lines, the transverse diameter 

 10 lines. 



Locality. The specimen forwarded to us by Mr. Bean is from the dark-gray shale of 

 the Great Oolite near Scarborough. It is only a cast, and much compressed, so that the 

 specific character cannot be sufficiently determined. 



Trochus Leckenbii. Plate XV, figs. 21, 21a. 



T. Testa conico-depressd, anfractibus (4 — 5) planis, costulis rotundatis crebris cinctis ; 



